用JAVA实现LL(1)文法语法分析程序

缺乏、安全感 2022-09-22 14:00 203阅读 0赞

一个简单语法分析器的设计与实现

实验目的：

1.掌握语法分析的基本任务；

2.掌握语法分析器的工作流程；

3.能设计一个简单的语法分析器，并完成对指定句子的分析。

实验内容：

给定一个LL（1）文法，编制语法分析程序，输出其预测分析表，用LL(1)预测分析程序实现其分析过程并输出分析过程和分析结果。

主要实验内容：

求出预测分析表，需要求解此文法的select集；而select集是由first集和follow集求解出来的。所以一般是先求出first集，再求出follow集，再最后求出select集。

由于题目要求的是会给定一个LL1文法。这里我就暂时假设输入的是一个LL1文法。（如果不是LL1的文法，含有左递归的话，需要先消除左递归

算法是：

对文法G：

S->Sa

S->b

可改写为：

S->bS'

S'->aS'|ε

)

## 1.first集求解主要算法 ##

分以下2种情况：

![Center][]

## 2.Follow求解算法 ##

分以下4种情况：

![Center 1][]

## 3.Select集求解算法 ##

分以下3种情况：

![Center 2][]

## 4.编程实现 ##

import java.io.Serializable;
    import java.util.ArrayList;
    import java.util.HashMap;
    import java.util.Iterator;
    import java.util.Set;
    import java.util.TreeMap;
    import java.util.TreeSet;
    
    import com.zhushoumao.bianyi.util.TextUtil;
    
    /**
     * @author PuHaiyang
     * @createTime 2016年6月10日 下午7:46:33
     * @email 761396462@qq.com
     * @function LL(1)文法
     *
     */
    public class Gs implements Serializable {
    
    	/**
    	 * 
    	 */
    	private static final long serialVersionUID = 1L;
    
    	public Gs() {
    		super();
    		gsArray = new ArrayList<String>();
    		nvSet = new TreeSet<Character>();
    		ntSet = new TreeSet<Character>();
    		firstMap = new HashMap<Character, TreeSet<Character>>();
    		followMap = new HashMap<Character, TreeSet<Character>>();
    		selectMap = new TreeMap<Character, HashMap<String, TreeSet<Character>>>();
    	}
    
    	private String[][] analyzeTable;
    
    	/**
    	 * Select集合
    	 */
    	private TreeMap<Character, HashMap<String, TreeSet<Character>>> selectMap;
    	/**
    	 * LL（1）文法产生集合
    	 */
    	private ArrayList<String> gsArray;
    	/**
    	 * 表达式集合
    	 */
    	private HashMap<Character, ArrayList<String>> expressionMap;
    	/**
    	 * 开始符
    	 */
    	private Character s;
    	/**
    	 * Vn非终结符集合
    	 */
    	private TreeSet<Character> nvSet;
    	/**
    	 * Vt终结符集合
    	 */
    	private TreeSet<Character> ntSet;
    	/**
    	 * First集合
    	 */
    	private HashMap<Character, TreeSet<Character>> firstMap;
    	/**
    	 * Follow集合
    	 */
    	private HashMap<Character, TreeSet<Character>> followMap;
    
    	public String[][] getAnalyzeTable() {
    		return analyzeTable;
    	}
    
    	public void setAnalyzeTable(String[][] analyzeTable) {
    		this.analyzeTable = analyzeTable;
    	}
    
    	public TreeMap<Character, HashMap<String, TreeSet<Character>>> getSelectMap() {
    		return selectMap;
    	}
    
    	public void setSelectMap(TreeMap<Character, HashMap<String, TreeSet<Character>>> selectMap) {
    		this.selectMap = selectMap;
    	}
    
    	public HashMap<Character, TreeSet<Character>> getFirstMap() {
    		return firstMap;
    	}
    
    	public void setFirstMap(HashMap<Character, TreeSet<Character>> firstMap) {
    		this.firstMap = firstMap;
    	}
    
    	public HashMap<Character, TreeSet<Character>> getFollowMap() {
    		return followMap;
    	}
    
    	public void setFollowMap(HashMap<Character, TreeSet<Character>> followMap) {
    		this.followMap = followMap;
    	}
    
    	public HashMap<Character, ArrayList<String>> getExpressionMap() {
    		return expressionMap;
    	}
    
    	public void setExpressionMap(HashMap<Character, ArrayList<String>> expressionMap) {
    		this.expressionMap = expressionMap;
    	}
    
    	public ArrayList<String> getGsArray() {
    		return gsArray;
    	}
    
    	public void setGsArray(ArrayList<String> gsArray) {
    		this.gsArray = gsArray;
    	}
    
    	public Character getS() {
    		return s;
    	}
    
    	public void setS(Character s) {
    		this.s = s;
    	}
    
    	public TreeSet<Character> getNvSet() {
    		return nvSet;
    	}
    
    	public void setNvSet(TreeSet<Character> nvSet) {
    		this.nvSet = nvSet;
    	}
    
    	public TreeSet<Character> getNtSet() {
    		return ntSet;
    	}
    
    	public void setNtSet(TreeSet<Character> ntSet) {
    		this.ntSet = ntSet;
    	}
    
    	/**
    	 * 获取非终结符集与终结符集
    	 * 
    	 * @param gsArray
    	 * @param nvSet
    	 * @param ntSet
    	 */
    	public void getNvNt() {
    		for (String gsItem : gsArray) {
    			String[] nvNtItem = gsItem.split("->");
    			String charItemStr = nvNtItem[0];
    			char charItem = charItemStr.charAt(0);
    			// nv在左边
    			nvSet.add(charItem);
    		}
    		for (String gsItem : gsArray) {
    			String[] nvNtItem = gsItem.split("->");
    			// nt在右边
    			String nvItemStr = nvNtItem[1];
    			// 遍历每一个字
    			for (int i = 0; i < nvItemStr.length(); i++) {
    				char charItem = nvItemStr.charAt(i);
    				if (!nvSet.contains(charItem)) {
    					ntSet.add(charItem);
    				}
    			}
    		}
    	}
    
    	/**
    	 * 初始化表达式集合
    	 */
    	public void initExpressionMaps() {
    		expressionMap = new HashMap<Character, ArrayList<String>>();
    		for (String gsItem : gsArray) {
    			String[] nvNtItem = gsItem.split("->");
    			String charItemStr = nvNtItem[0];
    			String charItemRightStr = nvNtItem[1];
    			char charItem = charItemStr.charAt(0);
    			if (!expressionMap.containsKey(charItem)) {
    				ArrayList<String> expArr = new ArrayList<String>();
    				expArr.add(charItemRightStr);
    				expressionMap.put(charItem, expArr);
    			} else {
    				ArrayList<String> expArr = expressionMap.get(charItem);
    				expArr.add(charItemRightStr);
    				expressionMap.put(charItem, expArr);
    			}
    		}
    	}
    
    	/**
    	 * 获取First集
    	 */
    	public void getFirst() {
    		// 遍历所有Nv,求出它们的First集合
    		Iterator<Character> iterator = nvSet.iterator();
    		while (iterator.hasNext()) {
    			Character charItem = iterator.next();
    			ArrayList<String> arrayList = expressionMap.get(charItem);
    			for (String itemStr : arrayList) {
    				boolean shouldBreak = false;
    				// Y1Y2Y3...Yk
    				for (int i = 0; i < itemStr.length(); i++) {
    					char itemitemChar = itemStr.charAt(i);
    					TreeSet<Character> itemSet = firstMap.get(charItem);
    					if (null == itemSet) {
    						itemSet = new TreeSet<Character>();
    					}
    					shouldBreak = calcFirst(itemSet, charItem, itemitemChar);
    					if (shouldBreak) {
    						break;
    					}
    				}
    			}
    		}
    	}
    
    	/**
    	 * 计算First函数
    	 * 
    	 * @param itemSet
    	 * @param charItem
    	 * @param itemitemChar
    	 * @return
    	 */
    	private boolean calcFirst(TreeSet<Character> itemSet, Character charItem, char itemitemChar) {
    		// get ago
    		// TreeSet<Character> itemSet = new TreeSet<Character>();
    		// 将它的每一位和Nt判断下
    		// 是终结符或空串,就停止，并将它加到FirstMap中
    		if (itemitemChar == 'ε' || ntSet.contains(itemitemChar)) {
    			itemSet.add(itemitemChar);
    			firstMap.put(charItem, itemSet);
    			// break;
    			return true;
    		} else if (nvSet.contains(itemitemChar)) {// 这一位是一个非终结符
    			ArrayList<String> arrayList = expressionMap.get(itemitemChar);
    			for (int i = 0; i < arrayList.size(); i++) {
    				String string = arrayList.get(i);
    				char tempChar = string.charAt(0);
    				calcFirst(itemSet, charItem, tempChar);
    			}
    		}
    		return true;
    	}
    
    	/**
    	 * 获取Follow集合
    	 */
    	public void getFollow() {
    		for (Character tempKey : nvSet) {
    			TreeSet<Character> tempSet = new TreeSet<Character>();
    			followMap.put(tempKey, tempSet);
    		}
    		// 遍历所有Nv,求出它们的First集合
    		Iterator<Character> iterator = nvSet.descendingIterator();
    		// nvSet.descendingIterator();
    
    		while (iterator.hasNext()) {
    			Character charItem = iterator.next();
    			System.out.println("charItem:" + charItem);
    			Set<Character> keySet = expressionMap.keySet();
    			for (Character keyCharItem : keySet) {
    				ArrayList<String> charItemArray = expressionMap.get(keyCharItem);
    				for (String itemCharStr : charItemArray) {
    					System.out.println(keyCharItem + "->" + itemCharStr);
    					TreeSet<Character> itemSet = followMap.get(charItem);
    					calcFollow(charItem, charItem, keyCharItem, itemCharStr, itemSet);
    				}
    			}
    		}
    	}
    
    	/**
    	 * 计算Follow集
    	 * 
    	 * @param putCharItem
    	 *            正在查询item
    	 * @param charItem
    	 *            待找item
    	 * @param keyCharItem
    	 *            节点名
    	 * @param itemCharStr
    	 *            符号集
    	 * @param itemSet
    	 *            结果集合
    	 */
    	private void calcFollow(Character putCharItem, Character charItem, Character keyCharItem, String itemCharStr,
    			TreeSet<Character> itemSet) {
    		///
    		// （1）A是S（开始符)，加入#
    		if (charItem.equals(s)) {
    			itemSet.add('#');
    			System.out.println("---------------find S:" + charItem + "   ={#}+Follow(E)");
    			followMap.put(putCharItem, itemSet);
    			// return;
    		}
    		// (2)Ab,=First(b)-ε,直接添加终结符
    		if (TextUtil.containsAb(ntSet, itemCharStr, charItem)) {
    			Character alastChar = TextUtil.getAlastChar(itemCharStr, charItem);
    			System.out.println("---------------find Ab:" + itemCharStr + "    " + charItem + "   =" + alastChar);
    			itemSet.add(alastChar);
    			followMap.put(putCharItem, itemSet);
    			// return;
    		}
    		// (2).2AB,=First(B)-ε,=First(B)-ε，添加first集合
    		if (TextUtil.containsAB(nvSet, itemCharStr, charItem)) {
    			Character alastChar = TextUtil.getAlastChar(itemCharStr, charItem);
    			System.out.println(
    					"---------------find AB:" + itemCharStr + "    " + charItem + "   =First(" + alastChar + ")");
    			TreeSet<Character> treeSet = firstMap.get(alastChar);
    			itemSet.addAll(treeSet);
    			if (treeSet.contains('ε')) {
    				itemSet.add('#');
    			}
    			itemSet.remove('ε');
    			followMap.put(putCharItem, itemSet);
    			///
    			if (TextUtil.containsbAbIsNull(nvSet, itemCharStr, charItem, expressionMap)) {
    				char tempChar = TextUtil.getAlastChar(itemCharStr, charItem);
    				System.out.println("tempChar:" + tempChar + "  key" + keyCharItem);
    				if (!keyCharItem.equals(charItem)) {
    					System.out.println("---------------find tempChar bA: " + "tempChar:" + tempChar + keyCharItem
    							+ "   " + itemCharStr + "    " + charItem + "   =Follow(" + keyCharItem + ")");
    					Set<Character> keySet = expressionMap.keySet();
    					for (Character keyCharItems : keySet) {
    						ArrayList<String> charItemArray = expressionMap.get(keyCharItems);
    						for (String itemCharStrs : charItemArray) {
    							calcFollow(putCharItem, keyCharItem, keyCharItems, itemCharStrs, itemSet);
    						}
    					}
    				}
    			}
    		}
    		// (3)B->aA,=Follow(B),添加followB
    		if (TextUtil.containsbA(nvSet, itemCharStr, charItem, expressionMap)) {
    			if (!keyCharItem.equals(charItem)) {
    				System.out.println("---------------find bA: " + keyCharItem + "   " + itemCharStr + "    " + charItem
    						+ "   =Follow(" + keyCharItem + ")");
    				Set<Character> keySet = expressionMap.keySet();
    				for (Character keyCharItems : keySet) {
    					ArrayList<String> charItemArray = expressionMap.get(keyCharItems);
    					for (String itemCharStrs : charItemArray) {
    						calcFollow(putCharItem, keyCharItem, keyCharItems, itemCharStrs, itemSet);
    					}
    				}
    			}
    		}
    	}
    
    	/**
    	 * 获取Select集合
    	 */
    	public void getSelect() {
    		// 遍历每一个表达式
    		// HashMap<Character, HashMap<String, TreeSet<Character>>>
    		Set<Character> keySet = expressionMap.keySet();
    		for (Character selectKey : keySet) {
    			ArrayList<String> arrayList = expressionMap.get(selectKey);
    			// 每一个表达式
    			HashMap<String, TreeSet<Character>> selectItemMap = new HashMap<String, TreeSet<Character>>();
    			for (String selectExp : arrayList) {
    				/**
    				 * 存放select结果的集合
    				 */
    				TreeSet<Character> selectSet = new TreeSet<Character>();
    				// set里存放的数据分3种情况,由selectExp决定
    				// 1.A->ε,=follow(A)
    				if (TextUtil.isEmptyStart(selectExp)) {
    					selectSet = followMap.get(selectKey);
    					selectSet.remove('ε');
    					selectItemMap.put(selectExp, selectSet);
    				}
    				// 2.Nt开始,=Nt
    				// <br>终结符开始
    				if (TextUtil.isNtStart(ntSet, selectExp)) {
    					selectSet.add(selectExp.charAt(0));
    					selectSet.remove('ε');
    					selectItemMap.put(selectExp, selectSet);
    				}
    				// 3.Nv开始，=first(Nv)
    				if (TextUtil.isNvStart(nvSet, selectExp)) {
    					selectSet = firstMap.get(selectKey);
    					selectSet.remove('ε');
    					selectItemMap.put(selectExp, selectSet);
    				}
    				selectMap.put(selectKey, selectItemMap);
    			}
    		}
    	}
    
    	/**
    	 * 生成预测分析表
    	 */
    	public void genAnalyzeTable() throws Exception {
    		Object[] ntArray = ntSet.toArray();
    		Object[] nvArray = nvSet.toArray();
    		// 预测分析表初始化
    		analyzeTable = new String[nvArray.length + 1][ntArray.length + 1];
    
    		// 输出一个占位符
    		System.out.print("Nv/Nt" + "\t\t");
    		analyzeTable[0][0] = "Nv/Nt";
    		// 初始化首行
    		for (int i = 0; i < ntArray.length; i++) {
    			if (ntArray[i].equals('ε')) {
    				ntArray[i] = '#';
    			}
    			System.out.print(ntArray[i] + "\t\t");
    			analyzeTable[0][i + 1] = ntArray[i] + "";
    		}
    
    		System.out.println("");
    		for (int i = 0; i < nvArray.length; i++) {
    			// 首列初始化
    			System.out.print(nvArray[i] + "\t\t");
    			analyzeTable[i + 1][0] = nvArray[i] + "";
    			for (int j = 0; j < ntArray.length; j++) {
    				String findUseExp = TextUtil.findUseExp(selectMap, Character.valueOf((Character) nvArray[i]),
    						Character.valueOf((Character) ntArray[j]));
    				if (null == findUseExp) {
    					System.out.print("\t\t");
    					analyzeTable[i + 1][j + 1] = "";
    				} else {
    					System.out.print(nvArray[i] + "->" + findUseExp + "\t\t");
    					analyzeTable[i + 1][j + 1] = nvArray[i] + "->" + findUseExp;
    				}
    			}
    			System.out.println();
    		}
    	}
    }

分析过程bean

import java.io.Serializable;
    
    /**
     * @author PuHaiyang
     * @createTime 2016年6月12日 下午4:15:37
     * @email 761396462@qq.com
     * @function 分析过程Bean
     *
     */
    public class AnalyzeProduce implements Serializable{
    	private static final long serialVersionUID = 10L;
    	private Integer index;
    	private String analyzeStackStr;
    	private String str;
    	private String useExpStr;
    
    	public Integer getIndex() {
    		return index;
    	}
    
    	public void setIndex(Integer index) {
    		this.index = index;
    	}
    
    	public String getAnalyzeStackStr() {
    		return analyzeStackStr;
    	}
    
    	public void setAnalyzeStackStr(String analyzeStackStr) {
    		this.analyzeStackStr = analyzeStackStr;
    	}
    
    	public String getStr() {
    		return str;
    	}
    
    	public void setStr(String str) {
    		this.str = str;
    	}
    
    	public String getUseExpStr() {
    		return useExpStr;
    	}
    
    	public void setUseExpStr(String useExpStr) {
    		this.useExpStr = useExpStr;
    	}
    
    }

句子分析器代码：

import java.util.ArrayList;
    import java.util.Stack;
    
    import com.zhushoumao.bianyi.pojo.AnalyzeProduce;
    import com.zhushoumao.bianyi.pojo.Gs;
    import com.zhushoumao.bianyi.util.TextUtil;
    
    /**
     * @author PuHaiyang
     * @createTime 2016年6月11日 下午11:27:00
     * @email 761396462@qq.com
     * @function 句子分析器
     *
     */
    public class Analyzer {
    
    	public Analyzer() {
    		super();
    		analyzeStatck = new Stack<Character>();
    		// 结束符进栈
    		analyzeStatck.push('#');
    	}
    
    	private ArrayList<AnalyzeProduce> analyzeProduces;
    
    	/**
    	 * LL（1）文法
    	 */
    	private Gs ll1Gs;
    
    	public Gs getLl1Gs() {
    		return ll1Gs;
    	}
    
    	public void setLl1Gs(Gs ll1Gs) {
    		this.ll1Gs = ll1Gs;
    	}
    
    	/**
    	 * 开始符
    	 */
    	private Character startChar;
    
    	/**
    	 * 分析栈
    	 */
    	private Stack<Character> analyzeStatck;
    	/**
    	 * 剩余输入串
    	 */
    	private String str;
    	/**
    	 * 推导所用产生或匹配
    	 */
    	private String useExp;
    
    	public ArrayList<AnalyzeProduce> getAnalyzeProduces() {
    		return analyzeProduces;
    	}
    
    	public void setAnalyzeProduces(ArrayList<AnalyzeProduce> analyzeProduces) {
    		this.analyzeProduces = analyzeProduces;
    	}
    
    	public Character getStartChar() {
    		return startChar;
    	}
    
    	public void setStartChar(Character startChar) {
    		this.startChar = startChar;
    	}
    
    	public Stack<Character> getAnalyzeStatck() {
    		return analyzeStatck;
    	}
    
    	public void setAnalyzeStatck(Stack<Character> analyzeStatck) {
    		this.analyzeStatck = analyzeStatck;
    	}
    
    	public String getStr() {
    		return str;
    	}
    
    	public void setStr(String str) {
    		this.str = str;
    	}
    
    	public String getUseExp() {
    		return useExp;
    	}
    
    	public void setUseExp(String useExp) {
    		this.useExp = useExp;
    	}
    
    	/**
    	 * 分析
    	 */
    	public void analyze() {
    		analyzeProduces = new ArrayList<AnalyzeProduce>();
    
    		// 开始符进栈
    		analyzeStatck.push(startChar);
    		System.out.println("开始符:" + startChar);
    		int index = 0;
    		// 开始分析
    		// while (analyzeStatck.peek() != '#' && str.charAt(0) != '#') {
    		while (!analyzeStatck.empty()) {
    			index++;
    			if (analyzeStatck.peek() != str.charAt(0)) {
    				// 到分析表中找到这个产生式
    				String nowUseExpStr = TextUtil.findUseExp(ll1Gs.getSelectMap(), analyzeStatck.peek(), str.charAt(0));
    				System.out.println(index + "\t\t\t" + analyzeStatck.toString() + "\t\t\t" + str + "\t\t\t"
    						+ analyzeStatck.peek() + "->" + nowUseExpStr);
    				AnalyzeProduce produce = new AnalyzeProduce();
    				produce.setIndex(index);
    				produce.setAnalyzeStackStr(analyzeStatck.toString());
    				produce.setStr(str);
    				if (null == nowUseExpStr) {
    					produce.setUseExpStr("无法匹配!");
    				} else {
    					produce.setUseExpStr(analyzeStatck.peek() + "->" + nowUseExpStr);
    				}
    				analyzeProduces.add(produce);
    				// 将之前的分析栈中的栈顶出栈
    				analyzeStatck.pop();
    				// 将要用到的表达式入栈,反序入栈
    				if (null != nowUseExpStr && nowUseExpStr.charAt(0) != 'ε') {
    					for (int j = nowUseExpStr.length() - 1; j >= 0; j--) {
    						char currentChar = nowUseExpStr.charAt(j);
    						analyzeStatck.push(currentChar);
    					}
    				}
    				continue;
    			}
    			// 如果可以匹配,分析栈出栈，串去掉一位
    			if (analyzeStatck.peek() == str.charAt(0)) {
    				System.out.println(index + "\t\t\t" + analyzeStatck.toString() + "\t\t\t" + str + "\t\t\t" + "“"
    						+ str.charAt(0) + "”匹配");
    				AnalyzeProduce produce = new AnalyzeProduce();
    				produce.setIndex(index);
    				produce.setAnalyzeStackStr(analyzeStatck.toString());
    				produce.setStr(str);
    				produce.setUseExpStr("“" + str.charAt(0) + "”匹配");
    				analyzeProduces.add(produce);
    				analyzeStatck.pop();
    				str = str.substring(1);
    				continue;
    			}
    		}
    
    	}
    
    }

测试类：

public class Main {
    
    	public static void main(String[] args) throws Exception {
    		// // LL（1）文法产生集合
    		ArrayList<String> gsArray = new ArrayList<String>();
    		// // Vn非终结符集合
    		// TreeSet<Character> nvSet = new TreeSet<Character>();
    		// // Vt终结符集合
    		// TreeSet<Character> ntSet = new TreeSet<Character>();
    		Gs gs = new Gs();
    		initGs(gsArray);
    		gs.setGsArray(gsArray);
    		// getNvNt(gsArray, gs.getNvSet(), gs.getNtSet());
    		gs.getNvNt();
    		gs.initExpressionMaps();
    		gs.getFirst();
    		// 设置开始符
    		gs.setS('E');
    		gs.getFollow();
    		gs.getSelect();
    		// 创建一个分析器
    		Analyzer analyzer = new Analyzer();
    		analyzer.setStartChar('E');
    		analyzer.setLl1Gs(gs);
    		analyzer.setStr("i+i*i#");
    		analyzer.analyze();
    		gs.genAnalyzeTable();
    		System.out.println("");
    	}
    
    	/**
    	 * 获取非终结符集与终结符集
    	 * 
    	 * @param gsArray
    	 * @param nvSet
    	 * @param ntSet
    	 */
    	private static void getNvNt(ArrayList<String> gsArray, TreeSet<Character> nvSet, TreeSet<Character> ntSet) {
    		for (String gsItem : gsArray) {
    			String[] nvNtItem = gsItem.split("->");
    			String charItemStr = nvNtItem[0];
    			char charItem = charItemStr.charAt(0);
    			// nv在左边
    			nvSet.add(charItem);
    		}
    		for (String gsItem : gsArray) {
    			String[] nvNtItem = gsItem.split("->");
    			// nt在右边
    			String nvItemStr = nvNtItem[1];
    			// 遍历每一个字
    			for (int i = 0; i < nvItemStr.length(); i++) {
    				char charItem = nvItemStr.charAt(i);
    				if (!nvSet.contains(charItem)) {
    					ntSet.add(charItem);
    				}
    			}
    		}
    
    	}
    
    	/**
    	 * 初始化LL(1)文法
    	 * 
    	 * @param gsArray
    	 */
    	private static void initGs(ArrayList<String> gsArray) {
    		gsArray.add("D->*FD");
    		gsArray.add("D->ε");
    		gsArray.add("T->FD");
    		gsArray.add("E->TC");
    		gsArray.add("F->(E)");
    		gsArray.add("F->i");
    		gsArray.add("C->+TC");
    		gsArray.add("C->ε");
    	}
    
    }

TextUtil 字符处理类：

import java.util.ArrayList;
    import java.util.HashMap;
    import java.util.Set;
    import java.util.TreeMap;
    import java.util.TreeSet;
    
    /**
     * @author PuHaiyang
     * @createTime 2016年6月11日 上午9:12:53
     * @email 761396462@qq.com
     * @function 字符工具类
     *
     */
    public class TextUtil {
    	/**
    	 * (3)B->aA,=Follow(B)
    	 * 
    	 * @param nvSet
    	 * @param itemCharStr
    	 * @param a
    	 * @param expressionMap
    	 * @return
    	 */
    	public static boolean containsbA(TreeSet<Character> nvSet, String itemCharStr, Character a,
    			HashMap<Character, ArrayList<String>> expressionMap) {
    		String aStr = a.toString();
    		String lastStr = itemCharStr.substring(itemCharStr.length() - 1);
    		if (lastStr.equals(aStr)) {
    			return true;
    		}
    		return false;
    
    	}
    
    	/**
    	 * 形如aBb,b=空
    	 * 
    	 * @param nvSet
    	 * @param itemCharStr
    	 * @param a
    	 * @param expressionMap
    	 * @return
    	 */
    	public static boolean containsbAbIsNull(TreeSet<Character> nvSet, String itemCharStr, Character a,
    			HashMap<Character, ArrayList<String>> expressionMap) {
    		String aStr = a.toString();
    		if (containsAB(nvSet, itemCharStr, a)) {
    			Character alastChar = getAlastChar(itemCharStr, a);
    			System.out.println("----------------+++++++++++++++++++--" + expressionMap.toString());
    			ArrayList<String> arrayList = expressionMap.get(alastChar);
    			if (arrayList.contains("ε")) {
    				System.out.println(alastChar + "  contains('ε')" + aStr);
    				return true;
    			}
    		}
    		return false;
    
    	}
    
    	/**
    	 * 是否包含这种的字符串<Br>
    	 * (2)Ab,=First(b)-ε,直接添加终结符
    	 * 
    	 * @param str
    	 * @param a
    	 * @return
    	 */
    	public static boolean containsAb(TreeSet<Character> ntSet, String itemCharStr, Character a) {
    		String aStr = a.toString();
    		if (itemCharStr.contains(aStr)) {
    			int aIndex = itemCharStr.indexOf(aStr);
    			String findStr;
    			try {
    				findStr = itemCharStr.substring(aIndex + 1, aIndex + 2);
    			} catch (Exception e) {
    				return false;
    			}
    			if (ntSet.contains(findStr.charAt(0))) {
    				return true;
    			} else {
    				return false;
    			}
    		} else {
    			return false;
    		}
    	}
    
    	/**
    	 * 是否包含这种的字符串<Br>
    	 * (2).2Ab,=First(b)-ε
    	 * 
    	 * @param str
    	 * @param a
    	 * @return
    	 */
    	public static boolean containsAB(TreeSet<Character> nvSet, String itemCharStr, Character a) {
    		String aStr = a.toString();
    		if (itemCharStr.contains(aStr)) {
    			int aIndex = itemCharStr.indexOf(aStr);
    			String findStr;
    			try {
    				findStr = itemCharStr.substring(aIndex + 1, aIndex + 2);
    			} catch (Exception e) {
    				return false;
    			}
    			if (nvSet.contains(findStr.charAt(0))) {
    				return true;
    			} else {
    				return false;
    			}
    		} else {
    			return false;
    		}
    	}
    
    	/**
    	 * 获取A后的字符
    	 * 
    	 * @param itemCharStr
    	 * @param a
    	 * @return
    	 */
    	public static Character getAlastChar(String itemCharStr, Character a) {
    		String aStr = a.toString();
    		if (itemCharStr.contains(aStr)) {
    			int aIndex = itemCharStr.indexOf(aStr);
    			String findStr = "";
    			try {
    				findStr = itemCharStr.substring(aIndex + 1, aIndex + 2);
    			} catch (Exception e) {
    				return null;
    			}
    			return findStr.charAt(0);
    		}
    		return null;
    	}
    
    	/**
    	 * 是否为ε开始的
    	 * 
    	 * @param selectExp
    	 * @return
    	 */
    	public static boolean isEmptyStart(String selectExp) {
    		char charAt = selectExp.charAt(0);
    		if (charAt == 'ε') {
    			return true;
    		}
    		return false;
    	}
    
    	/**
    	 * 是否是终结符开始的
    	 * 
    	 * @param ntSet
    	 * @param selectExp
    	 * @return
    	 */
    	public static boolean isNtStart(TreeSet<Character> ntSet, String selectExp) {
    		char charAt = selectExp.charAt(0);
    		if (ntSet.contains(charAt)) {
    			return true;
    		}
    		return false;
    	}
    
    	/**
    	 * 是否是非终结符开始的
    	 * 
    	 * @param nvSet
    	 * @param selectExp
    	 * @return
    	 */
    	public static boolean isNvStart(TreeSet<Character> nvSet, String selectExp) {
    		char charAt = selectExp.charAt(0);
    		if (nvSet.contains(charAt)) {
    			return true;
    		}
    		return false;
    	}
    
    	/**
    	 * 查找产生式
    	 * 
    	 * @param selectMap
    	 * @param peek
    	 *            当前Nv
    	 * @param charAt
    	 *            当前字符
    	 * @return
    	 */
    	public static String findUseExp(TreeMap<Character, HashMap<String, TreeSet<Character>>> selectMap, Character peek,
    			char charAt) {
    		try {
    			HashMap<String, TreeSet<Character>> hashMap = selectMap.get(peek);
    			Set<String> keySet = hashMap.keySet();
    			for (String useExp : keySet) {
    				TreeSet<Character> treeSet = hashMap.get(useExp);
    				if (treeSet.contains(charAt)) {
    					return useExp;
    				}
    			}
    		} catch (Exception e) {
    			return null;
    		}
    		return null;
    	}
    }

测试截图如下：

![Center 3][]

Web版如下：

![Center 4][]

![Center 5][]

部署链接：[点击打开此在线分析程序链接][Link 1]

为了大家测试方便，我把此程序上传到了GITHUB

项目地址：[https://github.com/puhaiyang/ll1analyzer.git][https_github.com_puhaiyang_ll1analyzer.git]

[Center]: /images/20220721/1958e08d8ba0476d829c40a214894fee.png
[Center 1]: /images/20220721/1609b9ecca0b461abd3ef8a0883a7321.png
[Center 2]: /images/20220721/ac5458a6dd5c478fb7bdfbc3efab3fea.png
[Center 3]: /images/20220721/dfaef39c29ab48d29066b311db715f3f.png
[Center 4]: /images/20220721/da78d4af2dc64c62bf191c3ea32ccfb3.png
[Center 5]: /images/20220721/937568d7dd324dd19d7d15fe832638ea.png
[Link 1]: http://www.zhushoumao.com/tool/index.html
[https_github.com_puhaiyang_ll1analyzer.git]: https://github.com/puhaiyang/ll1analyzer.git